Assuming solar metallicity might not be accurate because (i) important opacity sources could be locked up in large dust grains that remain in the midplane despite meridional circulation and thus do not accrete onto the planet; (ii) molecular abundances at a given position might not correspond to the chemical-equilibrium values at the local density and temperature, if the dynamical timescale is shorter than the chemical timescale [1]}, [2]}; and (iii) the accretion luminosity of the planet, in particular in the UV via photochemical reactions,
can also affect the chemical abundances [3]}.
Whether any of these effects will increase or decrease the opacity
cannot be said in general and is likely not robust against the details of the modelling.
